Without limiting the scope of the invention, its background is described in connection with the methods for treatment of brine and for reducing volumes of silica saturated membrane concentrates.
WIPO Patent Application Publication No. WO 2007/147198 (Fabig, 2007) describes a method and apparatus for improving the recovery of product liquid from a filter apparatus such as a reverse osmosis apparatus which includes operating the apparatus at or above a scaling threshold and when necessary cleaning the apparatus. The apparatus may use two units in parallel with one unit cleaning while the other unit is operating. The apparatus may be used to process reject brackish water from a reverse osmosis plant to minimize the amount of reject water.
U.S. Pat. No. 6,113,797 issued to Al-Samadi (2000) discloses a high water recovery membrane purification process. The '797 patent describes a two-stage high pressure high recovery process utilizing two reverse osmosis membrane systems intended to provide very high overall water recoveries from contaminated inorganic scale-containing water in an economical manner while preventing scale formation on the membrane and prolonging the useful life of the membrane. The first stage of the process involves using a low pressure membrane system to preconcentrate scale compounds while purifying the bulk volume of the scale-containing water (using antiscalants with pH control) and combining the influent water with a recycle stream of concentrate from the second stage membrane process in order to prevent scale formation. This first stage membrane system is followed by a second stage membrane system wherein the concentrate from the first stage membrane system is treated further at higher pressure in order to provide purification of the remaining preconcentrated stream and achieve very high overall water recoveries.
U.S. Pat. No. 6,508,936 issued to Hassan (2003) describes a desalination process in which combines two or more substantially different water treatment processes in a unique manner to desalinate saline water, especially sea water, to produce a high yield of high quality fresh water, including potable water, at an energy consumption equivalent to or less than much less efficient prior art desalination processes. The '936 patent describes a process wherein a nanofiltration step is synergistically combined with at least one of sea water reverse osmosis, multistage flash distillation, multieffect distillation of vapor compression distillation to provide an integrated desalination system by which sea water can be efficiently and economically converted to high quality potable water in yields which are at least 70%-80% greater than the yields available from the prior art processes. Typically a process of this invention using the nanofiltration initial step will produce, with respect to sea water feed properties, calcium, magnesium, sulfate, and bicarbonate ion content reductions of 63%-94%, pH decreases of about 0.4-0.5 units, and total dissolved solids content reductions of 35%-50%.